Excel VBA：从 HTML 中提取图像 Src 属性作为字符串

Question

我正在尝试抓取我的雇主网站以从他们的博客文章中大量提取图像。我已经开始使用 VBA 在 Excel 中创建一个抓取工具。

（我们无权访问 SQL 数据库）

我已经设置了一个工作表，其中包含 A 列中的帖子标识符列表和 B 列中帖子的 URL。

到目前为止，我的 VBA 脚本通过 B 列中的 URL 列表运行，使用 getElementById 从页面上的标签中提取 HTML，并将结果输出作为字符串粘贴到 C 列中。

我现在正试图弄清楚如何从结果输出中的每个图像中提取 src 属性并将其粘贴到相关列中。我一辈子都想不出一个简单的解决方案。我对 RegEx 不是很熟悉，并且正在努力使用 Excel 的内置字符串函数。

最终的游戏是让宏通过每个图像 URL 运行并将图像以“{Event No.}-{Image Number}”.jpg 之类的文件名格式保存到磁盘

任何帮助将不胜感激。

Worksheet setup

Sub Get_Image_SRC()

Dim sht As Worksheet
Dim LastRow As Long
Dim i As Integer
Dim url As String
Dim IE As Object
Dim objElement As Object
Dim objCollection As Object
Dim Elements As IHTMLElementCollection
Dim Element As IHTMLElement


Set sht = ThisWorkbook.Worksheets("Sheet1")
'Ctrl + Shift + End
LastRow = sht.Cells(sht.Rows.Count, "A").End(xlUp).Row
Set IE = CreateObject("InternetExplorer.Application")
IE.Visible = True
For i = 2 To LastRow
    url = Cells(i, "C").Value
    MsgBox (url)
    IE.navigate url
    Application.StatusBar = url & " is loading..."
    Do While IE.readyState = 4: DoEvents: Loop
    Do Until IE.readyState = 4: DoEvents: Loop
    Application.StatusBar = url & " Loaded"
    If Cells(i, "B").Value = "WEBNEWS" Then
        Cells(i, "D").Value = IE.document.getElementById("NewsDetail").outerHTML
       Else
        Cells(i, "D").Value = IE.document.getElementById("ReviewContainer").outerHTML
    End If



Next i

Set IE = Nothing
Set objElement = Nothing
Set objCollection = Nothing

End Sub

生成的 HTML 示例：

<div id=""NewsDetail""><div class=""NewsDetailTitle"">Video: Race Face Behind the Scenes Tour</div><div class=""NewsDetailImage""><img alt=""HeadlinesThumbnail.jpg"" src=""/ImageHandler/6190/515/1000/0/""></div>    <div class=""NewsDetailBody"">Pinkbike posted this video a while ago, if you missed it, its' definitely worth a watch. 

Ken from Camp of Champions took a look at their New Westminster factory last year which gives a look at the production, people and culture of Race Face. The staff at Race Face are truly their greatest asset they had, best wishes to everyone!

<p><center><object width=""500"" height=""281""><param name=""allowFullScreen"" value=""true""><param name=""AllowScriptAccess"" value=""always""><param name=""movie"" value=""http://www.pinkbike.com/v/188244""><embed width=""500"" height=""281"" src=""http://www.pinkbike.com/v/188244"" type=""application/x-shockwave-flash"" allowscriptaccess=""always"" allowfullscreen=""true""></object></center><p></p>


</div><div class=""NewsDate"">Published Friday, 25 November 2011</div></div>"

My current references

Answer 1

当您可以使用 Wget 轻松完成此操作时，使用 VBA 似乎非常复杂：How do I use Wget to download all Images into a single Folder。

Answer 2

对于正则表达式方法，您应该查看以下两个链接：

• Regular Expression to extract src attribute from img tag
• How to use Regular Expressions (Regex) in Microsoft Excel both in-cell and loops

这基本上归结为：

• 从img获取src属性值的正则表达式是src\s*=\s*"(.+?)"
• 使用 VBScript.RegExp 库在 VBA 中使用正则表达式

我使用了后期绑定，但您可以根据需要包含参考。

然后 VBA 是这样的：

选项显式

子测试()

Dim strHtml As String

' sample html, note single img tag
strHtml = ""
strHtml = strHtml & "<div id=""foo"">"
strHtml = strHtml & "<bar class=""baz"">"
strHtml = strHtml & "<img alt=""fred"" src=""\\server\path\picture1.png"" />"
strHtml = strHtml & "</bar>"
strHtml = strHtml & "<bar class=""baz"">"
strHtml = strHtml & "<img alt=""ned"" src=""\\server\path\picture2.png"" />"
strHtml = strHtml & "</bar>"
strHtml = strHtml & "<bar class=""baz"">"
strHtml = strHtml & "<img alt=""teddy"" src=""\\server\path\picture3.png"" />"
strHtml = strHtml & "</bar>"
strHtml = strHtml & "</div>"

Dim strSrc As String
Dim objRegex As Object
Dim objMatches As Object
Dim lngMatchCount As Long, lngCounter As Long

' create regex
Set objRegex = CreateObject("VBScript.RegExp")

' set pattern and execute
With objRegex
    .IgnoreCase = True
    .Pattern = "src\s*=\s*""(.+?)"""
    .Global = True

    If .Test(strHtml) Then
        Set objMatches = .Execute(strHtml)
        lngMatchCount = objMatches.Count
        For lngCounter = 0 To lngMatchCount - 1
            strSrc = objMatches(lngCounter).SubMatches(0)
            ' youve successfully captured the img src value
            Debug.Print strSrc
        Next
    Else
        strSrc = "Not found"
    End If
End With

结束子

请注意，我获取SubMatches 集合的第一项是为了获取src 属性的值。这段代码中objMatches(0)和objMatches(0).SubMatches(0)的区别是：

src="\\server\path\picture.png"

对比：

\\server\path\picture.png

您可能希望将其包装为一个函数，并在您的代码的 If..End If 块中计算出 IE.document.getElementById("NewsDetail").outerHTML 的值时调用它。